Field of the Invention
The present invention relates to a vehicle information display apparatus that provides information to a user and particularly to a vehicle information display apparatus that shortens a user's activation waiting time.
Description of the Related Art
As its function is highly advanced, a vehicle information display apparatus is equipped with an operating system and the like; thus, it takes a long time to activate it, as is the case with a car navigation apparatus; as a result, a user may have a feeling of irritation.
Moreover, a vehicle information display apparatus works as an instrument cluster. Meanwhile, in a conventional instrument cluster, all warning lamps are turned on when an engine is started and then the lamps for functions in good order are turned off. Therefore, in the case when an engine is started, if the vehicle information display apparatus has not been activated, the user has a feeling of irritation. Furthermore, a vehicle information display apparatus that performs a display function after the engine has been started indicates a delayed warning to the user, in comparison with a conventional instrument cluster.
To date, there have been known technologies that shorten the activation waiting time of a liquid-crystal device mounted in a vehicle (e.g., refer to Patent Document 1). In a conventional technology, a car navigation apparatus is triggered to be activated by locking a vehicle door while the screen thereof is dark, and then the display of the screen is started the moment the engine key switch is turned on.
[Patent Document 1] Japanese Patent No. 4206921
However, because when an engine is started, the starter activation current is large, the voltage drop across a battery mounted in the vehicle becomes large; thus, in the case where the display of the screen is started the moment the engine key switch is turned on or in the case where the vehicle information display apparatus is made to perform normal operation (the state where all functions can be utilized) when the engine key switch is turned on or immediately after the engine key switch has been turned on, the apparatuses mounted in the vehicle are reset. In order to prevent the reset, hardware measures are conceivable in which, for example, the battery capacity is increased or capacitors for preventing the reset are mounted in the power-supply circuits of the apparatuses; however, the cost increases. Moreover, especially, in a two-wheeled vehicle or the like, the mounting space is limited; thus, it is desirable that the hardware is downsized as much as possible.
Furthermore, it does not pose any problem even when a car navigation apparatus cannot be utilized immediately after the engine has been started; however, a instrument cluster is required to display the warning lamps and the engine speed immediately after the engine has been started. In the case where it is required to start the vehicle immediately after the engine has been started, vehicle information items such as the warning lamp, the fuel amount, the engine speed, the vehicle speed, and the like need to be displayed; therefore, the screen left being dark poses a problem.